Power-actuated workholder



Feb.26, 1929. 1,703,102

J.-EDGAR POWER ACTUA'IED WORKHOLDER Filed Oct. 30, 191524 5 Sheets-Sheet 1v Feb. 26, 4

J. EDGAR rowan ACTUATED wonflnown Fi1ed-.0ct. 30, 1924 5 Sheets-Sheet 2 Feb. 26, 1929.

rowan ACTUATED' wonxaomaa Filed Oct. 30, 1924 5 Sheets-Sheet 4 fin anion Q Jiow F Mm,

J. EDGAR rowan ACTUATED wbnxaowniz Feb. 2 1929.

Filed Oct. 30, 1924 5 Sfieets-Sheet Patented'Feb. 26, 1929.

UNITED STATES PATENT OFFICE.

JOHN EDGAR, OF ROCKFORD, ILLINOIS, ASSIGNOR TO BARBER-OOLMAN GOIHPAN Y, OF ROCKFORD, ILLINOIS, A CORPORATION OF ILLINOIS.

POWER-ACTUATED WORKI-IOLDER.

Application filed October 30, 1924. Serial No. 746,733.

My invention relates generally to work holders for machine tools, and has especial reference to an automatically operating machine wherein the machine operates continuously upon successive pieces of work inserted in the machine and removed therefrom by the operator.

The task of clamping and unclamping the work may, in some instances, render attendance upon the operation of such machines extremely laborious because the work must necessarily be held rigidly in the machine. Furthermore, it is desirable to reduce as much as possible the time consumed in the operation of inserting and removing the work. My aim has been to provide a work holder which is arranged to be power driven for the purpose of clamping and releasing the work, not only to eliminate the laborious character of the operation but to render it possible to increase the rate of production of the machine.

I attain this end by providing a work holder which is arranged to be connected with 5 the source of power under the control of a clutch whereby it may be readily connected and disconnected from the source of power.

The embodiment of my invention illustrated in the accompanying drawings and iereinafter fully described, is a work holder forming part of a gear roughing machine which is illustrated and described in my copending application Serial No. 694,916, filed February 25, 1924; and while my invention in its broader aspects is capable of general application, it is in certain of its features especially adapted for use in machines more particularly of the character of that disclosed in my said copending application.

Figure 1 of the drawings is a plan View of a gear roughing machine such as that shown in my said copending application Serial No. 694,916, and equipped with power driven work holders in accordance with my present invention.

Fig. 2 is a rear side view of said machine. Fig. 3 is a fragmentary vertical sectional view illustrating the connection between the main drive shaft of the machine and the two work holders thereon.

Fig. 4 is a similar view but showing another portion of the connection between the of the workholder looking from the left in F ig. 6.

Fig. 8 is a fragmentary sectional. View showing adetail of construction.

Fig. 9 is a horizontal sectional View taken zliqpproximately in the plane of line 9-9 of *igs. 10, 11 and 12 are fragmentary elevational views illustrating the operating levers for the work holder in various positions.

Fig. 13 is a fragmentary vertical sectional view on an enlarged scale illustrating a preferred form of screw-threaded connection between opposed sections of the work supporting means.

Referring to Figs. 1 and 2, the machine bed 10 carries centrally thereof a rotating hob or cutter 11 of large diameter. Carriages 12 and 13 are reciprocatedin ways 14 toward and from the cutter 11 on opposite sides thereof. Eaclrcarriage is equipped with'a work holding fixture 15 to which this invention has particular reference. It will be observed from the drawings that the fixtures 15 are oppositely inclined to the bed of the machine, the inclination being necessary in the present instance because of the helix angle of the hob cutter.

Each fixture comprises generally (Fig. 6) a blank-carrying spindle and means to rotate said spindle. The spindle is made of two separate parts mounted for relative longitudinal movement so as to be separable in order to receive between them the work which in the present instance is in the form of a gear blank a. The two sections are adapted to be connected together by means of interengaging screw-threads and one of the sections is connected with the source of power so as to be rotated in the gear-cutting operation, and the other section'is adapted to be connected with the source of power to clamp and unclamp the work under the control of a suitable clutch which in the present instance is manually operable. Inasmuch as both fixtures are in all substantial respects alike, I will confine my description thereof to the fixture on the carriage 13.

The fixture comprises a base portion 16 mounted on the carriage, and from this base portion rise bracket members 17 and 18 merging into a box or hearing head 19 at their up- )er ends to form in effect an open frame.

aid frame is disposed transversely of the periphery of the cutter, parallel to the axis thereof, and provides a rigid supporting structure for the work holder.

The base 16 provides a bearing 21 for the lower section 22 of the blank-carrying spindle. The spindle projects below the bearing 21 and carries at its lower end a driven gear 23 which in the present instance is a helical gear corresponding to the helical angle of the cutter 11 in order that it may mesh with the driving gear (not shown). Said lower section of the spindle may be mounted in its bearing 21 so as to be held against longitudinal movement, in any suitable way as, for example, that disclosed in my copending application Serial No. 728,354, filed July 26, 1924. At its upper end, this section has a blank-carrying disk or clamping collar 28 rigidly secured upon a cylindrical portion 29 of the spindle. The disk 28 acts as a clamping member in cooperation with another disk 30 mounted on the reduced lower end 31 of the upper section 32 of the spindle.

Said upper section. 32 of the spindle is mounted in the upper portion of the fixture framework in coaxial relation to the lower section and in such a way as to be rotatable and also axially movable toward and away from the lower spindle section 22. Thus, it is splined in a sleeve 33 in the upper bearing 19. The sleeve bears at opposite ends in annular members 34 and 35 which in turn are mounted in flanged bushings 36 and 37 in the upper and lower ends of the bearing 19. The member 35 has interposed between it and the sleeve 33 a bushing 38; and the member 34 has secured to itsupper end a disk or cap 39 by means of a screw 40, said cap having a central opening through which the spindle passes.

The reduced lower end 31 of the upper spindle section 32 is adapted to enter the central opening in the gear blank a when the latter has been placed centrally upon the disk 28, and to facilitate this movement, the extreme lower end of the upper spindle section is beveled as at 41. Also, it has an axial hole 42 adapted to receive the reduced upper end 43 of the lower spindle section 22. A chamber 44 is provided in the inner end of the hole 42 to receive dirt, chips or the like the lower reduced end 31 of the upper spindle section is internally threaded below the hole 42, as at 46, also conically, to coact with the conical screw 45. It will be observed that the angle of inclination is sufficiently great to permit the internally threaded member to drop over the externally threaded conical screw 45, into a position such that a fraction of a turn imparted to the upper spindle section 32 will effect the interengagement of the threads over their entire helical surfaces. Thus the connection or disconnection of the parts may be quickly effected, and moreover, the clamping strain is distributed equally over the entire lengths of the threaded members providing insurance against the strip ping of threads under the application of power.

The means which I have provided for retatingthe upper spindle 32 by the application of motive power comprises a bevel pinion 47 which is constantly driven in the operation of the machine and ivhich is arranged to be connected with the upper spindle 32 to rotate it in either one direction or the other under the control of a reversing clutch generally designated by the numeral 48. The pinion 47 is shown as mounted on a stud shaft 49 journaled in a bushing 49 within a bearing sleeve 50 which latter is secured by means of a screw 51 within a rearwardly extending cylindrical bearing head 52 carried by the upper end of the fixture framework.

The stud shaft 49 is connected by means of a universal joint designated generally by the numeral 53 with a short shaft 54 which in turn is connected by means of a universal joint 55 (Figs. 4 and 5) with a stud shaft 56 mounted in a housing 57. The universal joints 53 and 55 may be of any suitable or preferred construction and form per se no part of this invention. The housing 57 encloses the universal oint 55 and also encloses a bevel gear 58 meshing, in the case of the fixture on the carriage 13, with a pinion 59 on a longitudinally extending shaft 60 journaled in one side wall of the housing 57. Said shaft 60 extends at its opposite end into the housing 57 corresponding to the fixture on the carriage 12, and carries a bevel pinion 58 (Fig. 5) meshing with a bevel gear 59 Said pinion 58 also meshes with a bevel pinion 61 (Fig. 4) on the upper end of a shaft 62 which is journaled in the lower porvtion of the housing 57*. The lower end of bearing for the lowerend of the shaft 62.

The shaft 63 is connected with the source of power so as to be constantly driven in the operation of the machine.

The reversing clutch 48 (Fig. 6) whereby the connection and disconnection of the two spindle sections may be effected by the application of motive power comprises in the present instance a clutch collar 66 which is splined on the sleeve 33 (Figs. 6 and 9). At its upper end, said clutch sleeve has an outturned flange 67, and on the upper face of said flange I provide teeth or jaws 68 which are adapted to interengage with jaws 69 formed on the under side of a flange 70 on the lower end of the annular member 34. The jaws 68 and 69 are shaped so as positively to connect the parts together when interengaged. The flange 70 on the. member 34 is radially extended and securely fastened as by means of rivets 71 with a bevel gear 72 meshing at all times with the bevel pinion 47. Since the sleeve 66 has a sliding connection with the sleeve 33, and the spindle in turn has a slidable but nonrotatable engagement in the sleeve 33, when the sleeve 66 is moved to carry its jaws 68 into engagement with the jaws 69 of the member 34, the spindle is rotated. The arrangement is such that such rotation by the gear 72 is in a direction to unscrew or disconnect theupper spindle 32 from the lower spindle 22. In this operation the lower spindle is held stationary by reason of a worm drive connection with a source of power as shown in my said copending application Serial No. 694,916.

The lower end of the clutch sleeve 66 on the other hand has a frictional connection with the spindle '32, comprising in the present instance, a ring 73 screw-threaded upon the lower end of the sleeve 66. This ring has a friction ring 74 secured on its under side and adapted to coact with the upper face of a bevel gear wheel 75 also meshing constantly with the pinion 47 for rotation in a direction opposite to that of the gear 72. I The gear 75 is connected by rivets 76 with a flange 77 on the upper end of the sleeve 35 which is rotatable between thebushings 37 and 38. The direction of rotation imparted to the spindle section 32 by the gear wheel 75 when frictionally engaged with the ring 73 is such as to cause the interfitting conical screw-threads on the two spindle sections to interengage and clamp the work a between the members 28 and 30. Because of the frictional connection between the gear 75 and the clutch sleeve 66 it is unnecessary to limit the rotation of the gear to that of the sleeve.

The means for operating the clutch 48 preferably comprises a lever 7 (Figs. 6, and

-10 to 12) operatively' connected with the clutch collar 66 and arranged to be actuated by a spring 79 under the control of a cam I 80 by a hand lever 81.

The lever 78 is mounted between its ends ona shaft 82 journaled at opposite ends in bearings 83 provided in opposite sides of a housing plate 84 which serves to enclose the gears 7 2, 7 5 and associated parts. Said plate 84 has a slot 85-through which the lever projects and then depends downwardly for engagement with the cam 80. The opposite end of the lever is pivoted to a ring 86 entered in a groove'inthe clutch collar 66 formed between the flange 67 and the ring 73. The clutch collar is rotatable relative to said ring 86 andantifriction bearings 87 may be inserted between the ring 86 and the ring 73 for the purpose of eliminating friction between these parts when the clutch is operated to engage frictionally the ring 73 with the gear 75 and thus effect a frictional connection between the latter and the spindle section 32.

The lower outer end of the lever 78 carries a shoe 88 which is mounted upon a pin 89 carried by the lever and held against pivotal movement by means of adjusting screws 90 and 90 By this construction, the shoe is capable of adjustment relative to the lever 78. The spring 79 is anchored at one end on an extension of the pin 89 and at its other end is fast to a pin 91 near the upper end of the frame member 17. The spring 79 thus tends at all times to swing the lever 78 in a direction to operate the clutch collar 66 to cause its jaws 68 to engage with the jaws 69 rigid with the gear wheel 72, whereby to effect the unscrewing of the spindle section 32 from the section 22. I

The cam 80 is normally held in a position such as to be engaged by the shoe 88 under the action'of the spring 79 whereby to hold the clutch collar 66 in neutral position. This cam 80 is mounted on a stud shaft 92 near the upper end of the frame member 17 8), and a spring-pressed detent means 93 (Fig. 6) is adapted to engage with the cam member 80 to hold it in such neutral position. The detent means 93 may comprise a springpressed ball entered in a'bore 94 provided in a laterally offset portion at the upper end of the frame member 17 arranged to overlie the cam 80.

Rigid with the cam member 80 is the hand lever 81. For this purpose, the cam member has formed integral therewith a tubular extension 95 (Fig. 8), to the end of which the lever 81 is made fast asby means-of a key 96. As shown in Fig. 6, the cam 80 when in its neutral position is engaged by the lowermost corner or heel of the shoe 88 so thata downward movement of the cam by a corresponding operation of the hand lever 81 effects spindle section and thereby rotate the latter in a direction to screw it onto the lower spindle section.

When the upper spindle has been disconnec'ted from the lower spindle through a downward movement of the lever 81, it is desirable also to raise the upper spindle to separate it from the lower spindle and thus permit of the removal of one blank and the insertion of a new one. Such upward movement of the spindle 32 is accomplished in the present instance through the medium of the lever 81 by simply continuing its. downward movement. To this end I provide a lever arm 97 which is loosely mounted on the tubular extension 95 of the cam member 80 (Fig. 8) and is operatively connected with a flange or collar 98 on the spindle 32, the lever for this purpose being provided at its inner end with a slotted pin 99 engaging the collar 7). At its opposite end the lever arm 97 is shaped to provide a pair of stop fingers 100 and 101 between which is interposed a pin 102 carried by the lever 81. The arrangement is such that after the disengagement of the cam member 80 from the shoe 88 the continued downward movement of the lever 81 carries the pin 102 into engagement with the stop finger 101, thus effecting connection between the lever 81 and the lever arm 97 whereby the spindle 32 may be elevated, the same having in the meantime been operated so as to be released from the lower spindle'22. A lost motion connection is thus provided between the lever 81 and lever arm 97 which permits of the initial operation of the cam member to effect the disconnection of the two spindle sections and subsequently enables the operator to effect a separation between the two spindle sections. Conversely, the upper spindle section is permitted to descend by an upward operation of the lever 81, and if necessary the spindle may be urged downwardly by the engagement of the pin 102 with the stop finger 100 in such upward movement of the lever 81.

It will be observed from Fig. 0 that when the work is clamped in position between the two spindle sections, the lower end of the upper spindle enters the bore of the blank. It may therefore happen that when the two spindles are separated the blank may adhere to the upper spindle. I therefore provide a means for stripping the blank when necessary from the upper spindle in the upward movement of the latter. This means comprises a tubular member 103 mounted centrally of the frame of the fixture (Fig. 6) and adapted to be engaged by the blank as the latter travels upwardly with the spindle 32. The clamping disk 30 in this operation enters the member 103, being of a smaller external diameter than the internal diameter of said member, and the peripheral upper portion of the blank engages with the lower edge of the stripping member.

Summarizing theoperation of my power actuated work holder, the operator standing in front of the machine (Fig. 1) grasps the forwardly extending lever 81 which normally occupies a position corresponding to that shown in Figs. 6 and 10. Assuming that the machinehas just previously completed its operation upon a blank held in the work holder, the operator moves the lever 81 clownwardly to effect the disengagement of the cam member 80 rigid therewith from the shoe 88 on. the clutch operating lever 78. The latter then operates, under the action of the spring 79, to move the clutch collar 66 into positive connection with the bevel gear 72. The latter, it will be remembered, is constantly rotating in a counter-clockwise direction through the operation of the bevel pinion 17, which latter is connected with the source of power through connections includ ing universal joints 53 and provided to permit of the feeding movement of the fixtures upon their respective carriages. The parts being new in the position shown in Fig. 11, the operator continues the downward movement of the lever 81 in which the latter becomes connected with the lever arm 97 through the pin 102 and the stop finger 101, with the result that the upper spindle section 32 is raised to separate it from the lower spindle section and if necessary to strip the completed work a from the upper spindle. Upon such removal of the completed work, a new blank is placed upon the disk 28 and the lever 81 moved upwardly first to insure downward movement of the upper spindle 32 into operative association with the lower spindle 22, and then to move the cam member upwardly into engagement with the shoe 88, operating the clutch lever 78 to effect a frictional connection between the clutch collar 66 and the bevel gear 75. The latter continuously turning in a clockwise direction operates to connect the two spindle sections together. In this latter operation, it will be observed, (Fig. 13) the interfitting threaded portions of the two spindles engage substantially simultaneously through the entire length of their helices, which. serves to eliminate any thread stripping tendency and also effects the desired connection by a fractional turn of the upper section relative to the lower section.

I claim as my inventioni 1. A work holder comprising, in combination, a pair of clamping members adapted to receive the work between them, means for connecting said members together including two axially alined parts having ascrew threaded connection therebetween, and means for reversely rotating one of said parts including a pair of elements constantly driven in opposite directions and a clutch operating to connect said elements selectively with the part to be rotated.

' 2. A work holder comprising, in combination, a pair of clamping members adapted to receive the work between them, means for connecting said members together including two axially alined parts having a screwthre'aded connection therebetween, means for reversely rotating one of said parts includinga pair of'elements constantly driven in opposite directions'and a clutch operating toconnect said elements selectively with the parts to be rotated, and means for operating said clutch also adapted to effect axial movement between said parts when disconnected.

3. A work holder having means for clamping the work including two axially alined parts adapted to be connected or disconnected by the relative rotation of the parts, a driven element, and means operable to connect one of said parts with said element for rotation thereby in either one direction orthe'other.

4;. A work holder having means for clamping thework including two axially alined parts-adapted to be connected or disconnected by the relative rotation of the parts, a driven element, and means operable to connect one of said parts with said element for rotation thereby in either one direction or the other, said means comprisinga pair of gear elements actuated in opposite directions by said driven element, and means including a lever for effecting a connection between either one of said reversely rotating elements and the part to be rotated. v

5. A work holder comprising two axially alined parts mounted for relative longitud1- nal and rotational movements and adapted to be connected and disconnected by a rotary movement of one of the parts, and means including'a reversing clutch adapted for connection with a source of motive powerto rotate one of the parts in either one direction or the other.

6. A work holder comprising two axially alined parts mounted for relative axial and rotational movements and adapted to be connected by a rotation of one of the parts to clampthe work, means for sliding the part to be rotated in opposite directions, and means for controlling the last mentioned means whereby selectively to rotate said part in one direction or the other.,

7. Aiwork holder comprising two axially alined parts mounted for relative axial and rotational movements and adapted to be connected by a rotation of one of the parts to clamp the work, means for actuating the part to be rotated in opposite directions, and means for controlling the last mentioned meanswhereby selectively to rotate said part in one direction or the other, said controlling means comprising a lever normally tending to move in one direction and a cam for operating said lever.

8. A work holder comprising two axially alined parts mounted for relative axial and rotational movements and adapted to be connected by a rotation of one of the parts to clamp the work, means for actuating the part to be rotated in opposite directions, and means for controlling the last mentioned means whereby selectively to rotate said part in one directionor the other, said controlling means comprising a lever normally tending to move in one direction, a cam for operating said lever, and a second lever for operating said cam. p

9. A work holder comprising two axially alined parts mounted for relative axial and rotational movements and adapted to be connected by a rotation of one of the parts to clamp the work, means for actuating the part to be rotated in opposite directions, and means for controlling the last mentioned means whereby selectively to rotate said part in one direction or the other, said controlling means comprisng a lever normally tending to move in one direction and a cam for operating said lever, and a second lever for operating said cam, said second lever having an operative connection with the part to be rotated adapted to move it axially relative to the other part when disconnected therefrom.

10. A Work holding fixture comprising, in combination, two axially alined clamping parts mounted for rotational movement and having a screw-threaded connection between their adjacent ends, one of said parts being also mounted for axial movement so that it may be withdrawn from the other part to allow the insertion and removal of the work through the space between the adjacent ends of said parts, and means operatively connecting the axially movable part with a source of motive power to rotate it. v r

11. A work holding fixture comprising, in combination, clamping means including two axially alined parts mounted for rotational movements and having a screw-threaded connection between their adjacent ends, one of said parts being also mounted for axial movement so that it may be withdrawn from the other part to allow the insertion and removal of the work through the space between the adjacent ends of said parts, and means operatively connecting the axially movable part with a source of motive power torotate it, the screw-threaded connection between said parts comprising interfitting threaded members conical in form.

12. A work holding fixture comprising two axially movable parts mounted for rotary movements, means providing a screwthreaded connection between the parts adapted to clamp the work in position, said means comprising two inter-fitting conical members provided with interengaging screwthreads of conical form, and means for rel atively rotating the parts comprising a reversing clutch for connecting one of the parts with a source of power.

13. A work holding fixture comprising two clamping members, two axially alined parts carrying the respective clamping members upon adjacent end portions and mounted for relative rotary movements, said parts having upon their adjacent ends interfitting portions which are conical in form and are provided with interengaging screw-threads whereby to connect them, together.

14. A Work holder for milling machines and the like having a carriage and a drive mechanism, said work holder comprising two axially alined parts one of which is adapted to be driven and the other one of which is arranged to be connected with the drive mechanism for rotation thereby, means under the control of the operator for controlling the rotation of the last mentioned part, and means operating in such rotation of said part for clamping and unclamping the work between the parts.

15. The combination with a drive shaft connected with a source of motive power, of a work holder having two parts with a screwthreaded connection for clamping the work between them, and means for connecting one of said parts with said shaft to rotate it.

16. A work holding fixture having work clamping means including a member mounted for rotational and axial movements and adapted when rotated to clamp or unclamp the work, and means for connecting said member with a source of motive power to rotate it.

' 17. A work holding fixture having work clamping means including a member-mounted for rotational and axial movements and adapted when rotated to clamp or unclamp the work, means for connecting said member with a source of motive power to rotate it, and means for moving said member axially when in its inoperative position.

18. A work holder having, in combination with a positively driven element, two axially alined parts adapted to be screwed together, and means operable frictionally to connect one of said parts with said element to rotate the part, and means including a cam for controlling the last mentioned means.

19. A work holder having, in combination, two alined parts having a screw-threaded connection between them, means for rotating one of said parts, means for moving one of said parts axially to permit the insertion and removal of the work between the parts, and a.

single means for controlling the two last mentioned means.

20. A work holder having, in combination, two alined parts having a screw-threaded connection between them, means for rotating tween them, arranged to be connected or dis-- connected by relative rotary movement, a source of power, and clutch means arranged for connection with said power source to rotate one of said members in either direction selectively to connect or disconnect said memhere.

23. A work holder having, in combination, two clamping members, power means operable to actuate said members to unclamp the work, and a single manually operable means for controlling said power means and for separating said members to permit removal of the work.

24. A work holder having, in combination, two clamping members arranged to clamp vthe work between them, power means operable to clamp or unclamp the work, an element operable to shift one of said members into and out of clamping relation with the other member, and means for controlling said power means and operating said element. 1

25. A work holder having, in combination, two clamping members arranged to clamp the work between them, power means operable to clamp or unclamp the work, control means for said power means, an element operable to shift one of said elements into and out of clamping relation with the other member, and manually operable means to actuate said control means and element successively.

26. A work holder comprising, in combination, a pair of members for clamping apiece of work between them, power means operable to clamp or unclamp the work, means forcontrolling the application of said power means, an element operable to bring said members into or out of clamping relation, and hand operated means arranged'to actuate said control means and having alost motion connection with said elemen j V v 27. The combination of two'a lined rotary spindle-sections, clamping members on the adjacent end portions of said sections, one of said sections having a reduced end adapted to enter the central opening of a Work-piece placed between said clamping members, said reduced end and the end of the other section having interfitting conical screw-threaded portions for connecting said spindle-sections.

28. A Work-holder comprising a part mounted for rotation and longitudinal movement, clutch-controlled means for rotating said part in either direction, a lever for controlling said clutch-controlled means, a cam and a spring for moving said lever, a hand lever for oscillating the cam, a lever mounted on the axis of said hand lever and connected to the first mentioned part for moving the latter longitudinally, and a lost-motion connection between the hand lever and the last mentioned lever.

In testimony whereof, I have hereunto af- 20 

